Water less frequently. Increase light so plant can better absorb water.

Growth is slow and leaves are pale in color.

Lack of fertilizer

Apply appropriate fertilizer regularly throughout the growing season.

Growth is stunted, leaves are yellowed. A crustlike accumulation appears at the base of the plant's stem and on pot rim.

Buildup of mineral salts in the soil

In light cases, leach the soil thoroughly with clear water. In more severe cases, repot into fresh soil.

Plant does not bloom.

Various causes (too little light, too much water, etc.)

Improve growing conditions according to specific needs for each plant.

If pests are affecting your house plants, there is an increasingly wide range of biological pesticides, such as insecticidal soap, which can be used around the home without harming its other inhabitants.

It is important to use only appropriate pesticides in treating pests and diseases. Read the label carefully to make sure a pesticide is not only suited for the problem you wish to treat, but also to ensure that the product is not harmful to the plant you are treating. Always wear a mask, gloves, and long-sleeved clothing when working with chemical pesticides.

Organic pesticides are the preferred choice in an indoor environment. There are many very efficient organic insecticides and miticides -- insecticidal soap, diatomaceous earth, rubbing alcohol, rotenone, pyrethrine, etc. -- and powdered sulfur is a good organic fungicide.

The following chart will help you identify and treat plant conditions caused by pests.

House Plant Insects and Other Pests

Symptom

Cause

Treatment

Leaves take on a mottled appearance and appear dusty underneath. If the leaves are shaken over a sheet of white paper, tiny moving "spiders" are seen. In severe cases, a spidery webbing stretches between leaves.

Spider mites

Clean plant thoroughly with soapy water. Spray with insecticidal soap. Keep the air humid to prevent a recurrence.

Little balls of "cotton" (actually slow-moving insects or their egg cases) are seen on stems, at leaf axils, or on the plant's root system. Leaves yellow and may become covered with secretions.

Mealybugs

Touch individual insects and egg cases with a cotton swab dipped in rubbing alcohol. Spray the entire plant with a solution composed of 7 parts water and 1 part rubbing alcohol.

Shell- or scalelike bumps are seen on leaves and stems. Plants may yellow or become covered with secretions.

Scale insects

Scrape off the shells with an old toothbrush dipped in soapy water. Treat with insecticidal soap.

Green to black, round-bodied, translucent insects cluster together on new growth. Plants may yellow or become covered with secretions.

Aphids

Wash the plant thoroughly with a damp cloth dipped in soapy water. Treat with insecticidal soap.

Tiny, white, dandrufflike insects rise up when the plant is touched. Small translucent bumps are seen underneath the leaves.

Whiteflies

Use a vacuum to suck up flying adults, then wash the plant thoroughly with a damp cloth dipped in soapy water. Treat with insecticidal soap.

Leaves and foliage are streaked and mottled. Hyphen-sized insects scatter about when the plant is breathed upon. Tiny black excrements are found on infected plant parts.